Low-radiation film
By depositing silver, aluminum, titanium or alloy layers onto the base film, the shortcomings of existing low-emissivity glass and heat insulation films in terms of energy consumption and thermal insulation performance are solved, achieving high reflectivity and low emissivity, thereby improving the energy-saving effect and service life of buildings.
Patent Information
- Application Number
- CN202520134575.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2026-01-16
- Estimated Expiration
- 2035-01-21
AI Technical Summary
Existing low-emissivity glass and heat insulation films block solar heat gain in winter but cannot effectively block infrared heat radiation in summer, resulting in high building energy consumption. Furthermore, traditional heat insulation films have high surface emissivity and cannot effectively block infrared heat radiation heat exchange, thus lacking heat preservation function.
The base film made of ETFE has a protective layer on the outside and a dielectric layer and a radiation layer on the inside. The radiation layer has no protective layer and is naturally oxidized to form an oxide layer. Silver, aluminum, titanium or alloy layers are deposited on the base film through magnetron sputtering to form a low-emissivity film, achieving high reflectivity and low emissivity.
Achieving high reflectivity in the ultraviolet and near-infrared bands reduces the emissivity of the inner surface to below 0.08, improves thermal insulation performance by 3.5 times, extends service life by 25-35 years, significantly reduces solar heat gain in summer and energy consumption in winter, reduces building load, and saves construction costs.
Smart Images
Figure CN223806041U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a film technology, concretely relates to a low radiation film. BACKGROUND
[0002] The heat transfer energy consumption of building outer window and curtain wall glass accounts for more than 50% of the total building energy consumption, and all countries adopt low radiation glass technology to improve the heat preservation performance of outer window and curtain wall, the low radiation glass is that three layers of silver are plated on ordinary transparent glass through the magnetron sputtering method, the emissivity of glass surface is reduced (also called radiation rate), the emissivity of glass surface is reduced from 0.84 to below 0.2, and even to 0.01, the heat preservation performance of glass is greatly improved, and remarkable energy-saving effect is obtained.But there are also many problems, that is, the low radiation glass (low-E glass) seriously blocks the solar heat of building indoor during the sunshine in winter, and the calculation shows that the solar heat loss of building using low-E glass accounts for 30% of the building energy consumption.
[0003] Therefore, the film industry actively develops energy-saving films for building door and window curtain wall glass in order to reduce building energy consumption.But the heat insulation films popularized on the market generally rely on the surface reflection to block the solar radiation, so as to save the building air conditioning energy consumption.But due to the high surface emissivity of the existing heat insulation film, usually 0.7-0.9, the surface emissivity of most heat insulation films is higher than the emissivity of glass 0.84, cannot effectively block the infrared heat radiation, and does not have the heat preservation function.
[0004] Therefore, the utility model discloses a metal material is stacked and plated on the transparent soft film base material through magnetron sputtering and other methods, a transparent low-E soft film is obtained, the transparent low-E glass is replaced, the surface emissivity of building door and window curtain wall transparent system is adjusted through the winding and unwinding of the soft film, and the energy-saving performance of door and window curtain wall is improved. UTILITY MODEL CONTENTS
[0005] The utility model discloses a kind of low radiation films to overcome the deficiencies of above prior art, and the low radiation film can improve reflection effect, can effectively block the infrared heat radiation, and has good heat preservation function.
[0006] The utility model discloses a kind of low radiation films to overcome the deficiencies of above prior art, and the low radiation film can improve reflection effect, can effectively block the infrared heat radiation, and has good heat preservation function.
[0007] Preferably, the base film has a thickness of 15 μm or more and 1000 μm or less, and a visible light transmittance of 90% or more.
[0008] Preferably, when the radiation layer is one layer, the radiation layer has a thickness of 5-15 nm and the dielectric layer has a thickness of 0.1-2.5 nm; when the radiation layer has two layers, the first layer radiation layer has a thickness of 5-15 nm, the second layer radiation layer has a thickness of 10-30 nm, the first layer dielectric layer has a thickness of 0.1-2.5 nm, and the second layer dielectric layer has a thickness of 4-20 nm.
[0009] Preferably, the radiation layer is a silver layer, an aluminum layer, a titanium layer, or an alloy layer.
[0010] Preferably, the protective layer includes at least one of a metal layer, a metal nitride layer, and a semiconductor doped compound layer.
[0011] Preferably, when the dielectric layer has two layers, the first layer dielectric layer includes any one of a metal layer, a metal nitride layer, and a semiconductor doped compound layer, and the second layer dielectric layer includes any one of a metal fluoride layer, a metal nitride layer, and a semiconductor doped compound layer.
[0012] Preferably, the protective layer has a thickness of less than 20 nm.
[0013] The utility model discloses the following advantages relative to the prior art:
[0014] 1. The base film in the utility model is made of ETFE, and only the protective layer is arranged on the base film, the radiation layer is not arranged with the protective layer, the inner side of the radiation layer is naturally oxidized to form an oxide layer, and the low radiation film thus formed can reflect more than 90% of ultraviolet waves and more than 80% of near-infrared waves, achieving high reflection in both ultraviolet and near-infrared bands. Since ultraviolet light is greatly reflected, the damage of ultraviolet light to the low radiation film can be reduced, and the service life of the low radiation film is prolonged. At the same time, the hemispherical emissivity of the inner surface of the low radiation film is reduced to below 0.08, which is 3.5 times higher than the emissivity of 0.7 or more of conventional similar thermal insulation films, and the thermal insulation performance of the film structure is greatly improved.
[0015] 2. The base film in the utility model is made of ETFE, which has good durability. The low radiation film in the utility model has a service life of more than 25-35 years, which is 5-7 years longer than the service life of ordinary PET films, and has excellent physical and chemical properties, so as to achieve the same service life as the building envelope structure and reduce the replacement frequency or maintenance.
[0016] 3. The low-E film can be used as the inner sunshade roller shutter of the glass door and window and curtain wall in summer, or as the middle sunshade roller shutter of the hollow glass of the door and window curtain wall, which can significantly improve the direct reflection ratio of sunlight and the direct reflection ratio of infrared sunlight of the light transmission system of the curtain wall door and window, thereby greatly reducing the solar heat gain of the house in summer, reducing the air conditioning energy consumption of the house, and improving the thermal comfort of the room. The house in any climate zone is suitable for deploying the low-E film of the present application to block the solar radiation heat all day in summer.
[0017] 4. The low-E film can be used as the inner sunshade roller shutter of the glass door and window and curtain wall in winter, or as the middle sunshade roller shutter of the hollow glass of the door and window curtain wall, which can be rolled up in the period when the room needs passive solar heating, and can be unrolled in the period when the room needs heat preservation at night. The low-E film of the present application is suitable for use in any climate zone in winter, and the heat is gained during the day and the heat is preserved at sunset. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 is the structure diagram of the low-E film of the embodiment 1 of the present application.
[0019] Figure 2 is the solar waveband reflectance of the ordinary film.
[0020] Figure 3 is the solar waveband reflectance of the low-E film (i.e. low-E film) with a hemispherical emissivity of 0.17 of the embodiment 1 of the present application.
[0021] Figure 4 is the change of the hemispherical emissivity of the inner surface of the low-E film of the embodiment 1 of the present application with exposure time.
[0022] Figure 5 is the change of the heat transfer coefficient of the hollow glass with the hemispherical emissivity of the inner surface of the roller film of the embodiment 1 of the present application.
[0023] Figure 6 is the glass quality comparison of the three-glass two-cavity hollow glass with the built-in low-E film and the existing ordinary film and the low-E film of the embodiment 1 of the present application.
[0024] Figure 7 is the glass quality comparison of the four-glass three-cavity hollow glass with the built-in low-E film and the existing ordinary film and the low-E film of the embodiment 1 of the present application.
[0025] Figure 8 is the structure diagram of the low-E film of the embodiment 2 of the present application.
[0026] Figure 9The solar reflectance of the low-emissivity film (i.e., low-E film) with a hemispherical emissivity of 0.08 in Embodiment 2 of this utility model is as follows.
[0027] Among them, 1 is the base film, 2 is the protective layer, 3 is the dielectric layer, and 4 is the radiation layer. Detailed Implementation
[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0029] Example 1
[0030] like Figure 1 The low-emissivity film shown includes a base film made of ETFE, a protective layer on the outer side of the base film (i.e., the incident side of light), and a dielectric layer and a radiation layer on the inner side of the base film. Both the dielectric layer and the radiation layer are single layers, arranged sequentially away from the base film. Specifically, the radiation layer and the base film are connected by the dielectric layer to enhance the adhesion between them. The radiation layer is formed using a vacuum magnetron sputtering roll-to-roll deposition process. The thickness of the base film is greater than or equal to 15 μm and less than or equal to 1000 μm, and the visible light transmittance of the base film is greater than 90%. The thickness of the radiation layer is 5–15 nm, and the thickness of the dielectric layer is 0.1–2.5 nm. The radiation layer is a silver layer, an aluminum layer, a titanium layer, or an alloy layer. The protective layer includes at least one of a metal layer, a metal nitride layer, and a semiconductor doped compound layer. The thickness of the protective layer is less than 20 nm.
[0031] This low-emissivity film exhibits a reflectance of over 90% in the ultraviolet band and over 80% in the near-infrared band, achieving high reflectivity in both ultraviolet and near-infrared wavelengths. Because ultraviolet light is significantly reflected, damage to the low-emissivity film from ultraviolet light is reduced, extending its service life.
[0032] Furthermore, the protective layer is no longer installed inside the radiating layer, allowing it to oxidize naturally through direct contact with air. This reduces the hemispherical emissivity of the inner surface of the low-E film to below 0.08, while the emissivity of similar heat insulation films is above 0.7. In comparison, the low-E film of this invention improves infrared radiation heat blocking performance by more than 3.5 times, significantly enhancing the thermal insulation performance of the film structure. Using a low-E film with an emissivity below 0.2 in door, window, and curtain wall glass systems improves thermal insulation performance by more than 23.3% compared to using a film with an emissivity greater than 0.7 (the heat transfer coefficient decreases by at least 23.3%).
[0033] like Figure 2 The hemispherical emissivity of the ordinary film shown is 0.7, and the near-infrared reflectance is less than 70%. Figure 3 The hemispherical emissivity of the first low-emissivity film in this embodiment is reduced to 0.17, and the near-infrared reflectance is greater than 80%.
[0034] As Figure 4 shown, the prepared low-emissivity film sample with a hemispherical emissivity of 0.17 is directly exposed to the indoor air environment, and after about two months of natural oxidation test, the emissivity is always in the fluctuation range of 0.19-0.21, and there is no obvious change. That is, the radiation layer in the low-emissivity film of the utility model can have stable performance even without a protective layer, and the inner side of the radiation layer is naturally oxidized, which meets the use requirements.
[0035] As Figure 5 shown, taking a double-glass hollow glass with 6+12A+6 as an example, its heat transfer coefficient is 2.66 W / (m2·K), and after embedding an ordinary film with an emissivity of 0.7, its heat transfer coefficient can be reduced to 2.16 W / (m2·K), and the heat preservation performance is improved by 18.8%; after embedding a low-emissivity film with an emissivity of 0.2, the heat transfer coefficient can be further reduced to 1.94 W / (m2·K), and the heat preservation performance is improved by 27.1%. In addition, compared with using a soft film with an emissivity greater than 0.7, the use of a low-E film with an emissivity less than 0.2 in the embedded roll film glass system improves the heat preservation performance by more than 10.2% (at least 10.2% reduction in heat transfer coefficient).
[0036] As Figure 6 and Figure 7 shown, the hollow glass system embedded with the low-emissivity film significantly reduces the weight of the traditional three-glass two-cavity hollow glass and four-glass three-cavity hollow glass system by 30%-50%, greatly reduces the load of the glass curtain wall building, and saves the construction cost.
[0037] The experimental data of the above Figures 2 to 7 are obtained by the following method:
[0038] Reflectance: The reflectance of the low-emissivity film surface in the wavelength range of 0.3-2.5 μm is measured by a spectrophotometer at an incident angle of 5°, and the weighted average reflectance of the wavelength range of 0.3 μm-0.38 μm, 0.38 μm-0.78 μm, 0.78 μm-2.5 μm, and 0.3 μm-2.5 μm is calculated according to GB T 2680-2021 "Determination of the solar energy total transmittance, ultraviolet transmittance, and related parameters of window glass Visible light transmittance, solar light direct of building glass", respectively, as the values of ultraviolet light reflectance, visible light reflectance, near-infrared light reflectance, and solar light reflectance. In addition, the incident angle refers to the angle relative to the line perpendicular to the film surface.
[0039] Hemispherical emissivity: The surface hemispherical emissivity of the heat preservation and sunshade radiation cooling film is measured by a radiometer, and the test method follows the standard of American ASTM C1371 "Standard Test Method for Radiant Emittance of Materials Near Room Temperature Using Portable Emissometers".
[0040] Example 2
[0041] The low-emissivity film in this embodiment is the same as in Embodiment 1, except for the following technical features: Figure 8 As shown, in this embodiment, both the dielectric layer and the radiating layer are two layers, and they are alternately arranged along the direction away from the base film. The first dielectric layer includes any one of a metal layer, a metal nitride layer, and a semiconductor doped compound layer, and the second dielectric layer includes any one of a metal fluoride layer, a metal nitride layer, and a semiconductor doped compound layer. The thickness of the first radiating layer is 5–15 nm, the thickness of the second radiating layer is 10–30 nm, the thickness of the first dielectric layer is 0.1–2.5 nm, and the thickness of the second dielectric layer is 4–20 nm.
[0042] like Figure 9 As shown, the hemispherical emissivity of the low-emissivity film in this embodiment is reduced to 0.08, and the near-infrared reflectance is greater than 90%. After incorporating a low-emissivity film with an emissivity of 0.08, the heat transfer coefficient can be further reduced to 1.87 W / (m2·K), and the thermal insulation performance is improved by 29.7%.
[0043] The above-described specific embodiments are preferred embodiments of this utility model and are not intended to limit this utility model. Any other changes or equivalent substitutions made without departing from the technical solution of this utility model are included within the protection scope of this utility model.
Claims
1. A low-emissivity film characterized by: The base film is made of ETFE, a protective layer is arranged on the outer side of the base film, a medium layer and a radiation layer are arranged on the inner side of the base film, the medium layer and the radiation layer are both one layer and are arranged in turn away from the base film; or the medium layer and the radiation layer are both two layers and are arranged alternately away from the base film.
2. The low-e film of claim 1, wherein: The thickness of the base film is greater than or equal to 15 μm and less than or equal to 1000 μm, and the visible light transmittance of the base film is greater than 90%.
3. The low-e film of claim 1, wherein: When the radiation layer is one layer, the thickness of the radiation layer is 5-15 nm, and the thickness of the medium layer is 0.1-2.5 nm; when the radiation layer has two layers, the thickness of the first layer of radiation layer is 5-15 nm, the thickness of the second layer of radiation layer is 10-30 nm, the thickness of the first layer of medium layer is 0.1-2.5 nm, and the thickness of the second layer of medium layer is 4-20 nm.
4. The low-e film of claim 1, wherein: The radiation layer is a silver layer, an aluminum layer, a titanium layer or an alloy layer.
5. The low-e film of claim 1, wherein: The protective layer comprises at least one of a metal layer, a metal nitride layer and a semiconductor doped compound layer.
6. The low-e film of claim 1, wherein: When the medium layer has two layers, the first layer of medium layer comprises any one of a metal layer, a metal nitride layer and a semiconductor doped compound layer, and the second layer of medium layer comprises any one of a metal fluoride layer, a metal nitride layer and a semiconductor doped compound layer.
7. The low-e film of claim 1, wherein: The thickness of the protective layer is less than 20 nm.